Spray and Combustion Characteristics of Hydrocarbon Fuel Injected from Pressure-Swirl Nozzles

English

This paper presents spray and combustion characteristics of hydrocarbon fuel injected from pressure-swirl nozzles. Three commercial nozzles with orifice diameters of 0.256, 0.308 and 0.333 ㎜ and injection pressures ranging from 0.7 to 1.3 ㎫ were selected for the experiments. Spray characteristics such as breakup length, spray angle and drop size (SMD) were analyzed using photo image analyses and Malvern Particle Size Analyzer. The drop size was measured with and without a blower at the same measuring locations. The flame length and width were measured using photo image analyses. The temperature distribution along the axial distance and the gas emission such as CO, CO₂ and NOx were studied. The breakup length decreased with an increase in injection pressure for each nozzle but increased with an increase in nozzle orifice diameter. The spray angle increased and SMD decreased with an increase in injection pressure. The flame length increased linearly with an increase in injection pressure and in nozzle orifice diameter. The flame temperature increased with an increase in injection pressure but decreased along the axial distance. The maximum temperatures occurred closer to the burner exit and flame at axial distance of 242 mm from the diffuser tip. The experimental results showed that the level of CO decreased while that of CO₂ and NOx increased with an increase in injection pressure and nozzle orifice diameter.

Laryea, G.N.; No, S.Y.